Liquid Crystal Display Orientation Film Decomposition Control
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Solution Overview
Problem
Existing liquid crystal display devices using light orientation films face degradation in afterimage characteristics, thermal stability, and electric stability due to the presence of decomposition products from ultraviolet light irradiation, which affect the pretilt angle and directionality of liquid crystal molecules.
Innovation Solution
Regulating the residual amount of decomposition products in the light orientation film to ensure it remains between 0.1 ng and 500.0 ng per unit area, thereby inhibiting ion adsorption and improving the quality of image display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light orientation treatment is performed on polyimide resin orientation film, then pretilt angle and directionality are generated, but decomposition products are generated that degrade afterimage characteristics and thermal stability
Solution Approach 1:
The patent applies parameter changes by controlling the irradiation conditions (ultraviolet light intensity, irradiation time, wavelength) to regulate the decomposition product generation. By adjusting these parameters, the patent achieves an optimal balance where sufficient pretilt angle is generated while decomposition products are minimized to acceptable levels, thereby improving afterimage characteristics without completely eliminating the harmful effects.
Solution Approach 2:
The patent converts the harmful decomposition products into a controlled parameter by establishing a specific range (0.1-500.0 ng per unit area) for their acceptable presence. Instead of completely eliminating decomposition products, the patent finds that within this controlled range, they can coexist with the orientation function, and the harmful effects are significantly reduced while maintaining display performance.
2Reliability
If light orientation treatment is performed on polyimide resin orientation film, then pretilt angle and directionality are generated, but thermal stability is reduced due to decomposition products
Solution Approach 1:
The patent uses parameter changes by optimizing the ultraviolet light irradiation conditions (intensity, duration, wavelength) to control the extent of photodecomposition. By adjusting these parameters, the patent ensures that sufficient pretilt angle is achieved while limiting the generation of decomposition products that would otherwise severely compromise thermal stability.
Solution Approach 2:
The patent transforms the harmful thermal degradation effect into a controllable parameter by establishing an acceptable range for decomposition product content (0.1-500.0 ng per unit area). Within this range, the thermal stability is maintained at acceptable levels while still benefiting from the light orientation treatment.
3Reliability
If light orientation treatment is performed on polyimide resin orientation film, then pretilt angle and directionality are generated, but electric stability is reduced due to decomposition products
Solution Approach 1:
The patent applies parameter changes by controlling the photodecomposition extent through irradiation condition optimization. By adjusting ultraviolet light parameters, the patent ensures that the orientation function is sufficiently achieved while limiting decomposition product generation that would otherwise severely impact electric stability and ion adsorption characteristics.
Solution Approach 2:
The patent converts the harmful electric stability degradation into a manageable parameter by establishing a controlled range for decomposition product content (0.1-500.0 ng per unit area). Within this range, the electric stability and ion adsorption properties are maintained at acceptable levels while still achieving the desired orientation control function.
4Reliability
If rubbing treatment is used for orientation control, then orientation function is provided to orientation film, but contact treatment complexity and potential contamination are introduced
Solution Approach 1:
The patent replaces the mechanical rubbing treatment with a photopolymerization-based light orientation treatment. Instead of using mechanical friction to align molecules, the patent uses ultraviolet light irradiation to induce photopolymerization reactions that create cross-linked structures providing the desired orientation control function without mechanical contact.
Solution Approach 2:
The patent introduces ultraviolet light as an intermediary to transfer orientation control function without direct mechanical contact. The UV light acts as a mediator that induces chemical changes in the orientation film, achieving the same functional result as rubbing treatment but through a non-contact photchemical process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances afterimage characteristics, thermal stability, and electric stability by controlling the amount of decomposition products, leading to high-quality image display and improved reliability of liquid crystal display devices.
Implementation Method 1
an orientation film is irradiated with ultraviolet polarized light, and an excited state by a light energy reaction is used to cause a new bond formation reaction or bond cleavage reaction to occur in molecular chains of the orientation film
Implementation Method 2
the generation amount of fine decomposition product by cutting of ultraviolet rays is not considered
Implementation Method 3
When the orientation film has an ion adsorption site, an ion in the liquid crystal repeats the adsorption to and release from the adsorption site
Data Source
AI summary
In a liquid crystal display device using a photodecomposition type light orientation film, the deterioration of display performance due to an impurity resulting from a light orientation treatment of the orientation film is suppressed to enable high-quality image display. In the orientation film to which a liquid crystal orientation function is provided, the amount of decomposition product due to the orientation film is 3957.5 ng or less per 100 cm2.